Apparatus and system for expanding expandable polymeric microspheres

ABSTRACT

An apparatus including: (a) a steam generator having a power output of less than or equal to about 6 boiler horsepower; (b) a steam conduit in fluid communication with the steam generator; (c) a fluid material conduit in fluid communication with a source of a fluid material, wherein the fluid material includes unexpanded, expandable polymeric microspheres; (d) a treatment zone in fluid communication with the steam generator via the steam conduit, and with the fluid material conduit, such that the fluid material is contacted by steam within the treatment zone; and (e) a back pressure generator in fluid communication with the treatment zone, capable of increasing pressure in the treatment zone, which results in expansion of the expandable polymeric microspheres when the fluid material exits the treatment zone.

This application is a continuation application of InternationalApplication No. PCT/US2013/037455 filed on Apr. 19, 2013, and acontinuation-in-part application of U.S. Ser. No. 13/866,702 filed onApr. 19, 2014, both of which claim the benefit of the filing date under35 U.S.C. §119(e) from U.S. Provisional Applications For Patent Ser. No.61/790,312 filed on Mar. 15, 2013, Ser. No. 61/695,134 filed on Aug. 30,2012, and Ser. No. 61/635,562 filed on Apr. 19, 2012.

Provided is an apparatus for expanding expandable polymericmicrospheres.

Freeze-thaw cycles can be extremely damaging to water-saturated hardenedcementitious compositions, such as concrete. The best known technique toprevent or reduce the damage done is the incorporation in thecomposition of microscopically fine pores or voids. The pores or voidsfunction as internal expansion chambers and can therefore protect thecomposition from freeze-thaw damage by relieving changes in hydraulicpressure caused by freeze-thaw cycling. A conventional method used forproducing such voids in cementitious compositions is by introducingair-entraining agents into the compositions, which stabilize tinybubbles of air that are entrapped in the composition during mixing.

Unfortunately, this approach of producing air voids in cementitiouscompositions is plagued by a number of production and placement issues,some of which are the following:

Air Content: Changes in air content of the cementitious composition canresult in a composition with poor resistance to freeze-thaw damage ifthe air content drops with time or reduce the compressive strength ofthe composition if the air content increases with time. Examples arepumping a cementitious composition (decreasing air content bycompression), job-site addition of a superplasticizer (often elevatesair content or destabilizes the air void system), and interaction ofspecific admixtures with the air-entraining surfactant (that couldincrease or decrease air content).

Air Void Stabilization: The inability to stabilize air bubbles may becaused by the presence of materials that adsorb the stabilizingsurfactant, i.e., fly ash having high surface area carbon orinsufficient water for the surfactant to work properly, i.e, low slumpconcrete.

Air Void Characteristics: Formation of bubbles that are too large toprovide resistance to freezing and thawing damage may be the result ofpoor quality or poorly graded aggregates, use of other admixtures thatdestabilize the bubbles, etc. Such voids are often unstable and tend tofloat to the surface of the fresh concrete.

Overfinishing: Removal of air by overfinishing, removes air from thesurface of the concrete, typically resulting in distress by scaling ofthe detrained zone of cement paste adjacent to the overfinished surface.

The generation and stabilization of air at the time of mixing andensuring it remains at the appropriate amount and air void size untilthe cementitious composition hardens remain the largest day-to-daychallenges for the cementitious composition producer in North America.The air content and the characteristics of the air void system entrainedinto the cementitious composition cannot be controlled by directquantitative means, but only indirectly through the amount and/or typeof air-entraining agent added to the composition.

Factors such as the composition and particle shape of the aggregates,the type and quantity of cement in the mix, the consistency of thecementitious composition, the type of mixer used, the mixing time, andthe temperature all influence the performance of the air-entrainingagent. The void size distribution in ordinary air-entrained concrete canshow a very wide range of variation, between 10 and 3,000 micrometers(μm) or more. In such cementitious compositions, besides the small voidswhich are essential to cyclic freeze-thaw damage resistance, thepresence of larger voids, which contribute little to the durability ofthe cementitious composition and could reduce the strength of thecomposition, has to be accepted as an unavoidable feature.

Air-entraining agents have been shown to provide resistance tofreeze-thaw damage, as well as scaling damage resistance, which occurswhen the surface of the hardened cementitious composition breaks awayfor any of a number of reasons, some of which are discussed above.However, because conventional air-entraining agents suffer from theproblems discussed above, the cementitious composition industry issearching for new and better admixtures to provide the properties whichare currently provided by conventional air-entraining agents.

A recent development is to use polymeric microspheres to createcontrolled-size voids within cementitious compositions. However,development is still ongoing to improve the function of polymericmicrospheres within cementitious compositions, and to reduce the cost ofincluding polymeric microspheres in cementitious compositions.

In order to provide appropriately sized air voids, polymericmicrospheres may need to be expanded prior to incorporation intocementitious compositions. After expansion, expanded polymericmicrospheres may have up to about 75 times the volume of the unexpandedmicrospheres. Providing cementitious composition admixtures whichinclude expanded polymeric microspheres can be expensive, due to thehigh shipping cost associated with shipping an admixture which includeshigh-volume expanded microspheres, particularly if provided in anaqueous slurry which may include a volume of water.

Attempts have been previously made to find solutions to the problemidentified above, namely the high shipping costs associated withproviding expanded polymeric microspheres to end users. However,previous apparatus for expanding expandable polymeric microspheresconsume large amounts of energy and are very large in size. It has nowbeen surprisingly found that expandable polymeric microspheres may beadequately expanded using apparatus which consume much less energy andare significantly smaller in size.

For example, in certain previous apparatus utilized in expandingexpandable polymeric microspheres, steam generators capable of providingat least 30 boiler horsepower have been used. The present apparatusutilizes a steam generator having a power output of less than or equalto about 6 boiler horsepower to adequately expand the expandablepolymeric microspheres. This results in increased energy efficiency,lower costs, and an apparatus which is smaller in size, or footprint,than previous expansion apparatus.

What is needed is a means for delivering expanded polymeric microspheresto end users in a cost-effective manner.

Embodiments of the subject matter are disclosed with reference to theaccompanying drawings and are for illustrative purposes only. Thesubject matter is not limited in its application to the details ofconstruction or the arrangement of the components illustrated in thedrawings. Like reference numerals are used to indicate like components,unless otherwise indicated.

FIG. 1 is a schematic flowchart depicting one embodiment of the presentsubject matter.

FIG. 2 is a schematic flowchart depicting a second embodiment of thepresent subject matter.

Provided is an apparatus comprising: (a) a steam generator having apower output of less than or equal to about 6 boiler horsepower; (b) asteam conduit in fluid communication with the steam generator; (c) afluid material conduit in fluid communication with a source of a fluidmaterial, wherein the fluid material comprises unexpanded, expandablepolymeric microspheres; (d) a treatment zone in fluid communication withthe steam generator via the steam conduit, and with the fluid materialconduit, such that the fluid material is contacted by steam within thetreatment zone; and (e) a back pressure generator in fluid communicationwith the treatment zone, capable of increasing pressure in the treatmentzone, which results in expansion of the expandable polymericmicrospheres when the fluid material exits the treatment zone. Boilerhorsepower is a unit used to rate the power output of steam generators,and 1 boiler horsepower is equivalent to 13.15 horsepower, 9,809.5 wattsand 34.5 pounds of water evaporated per hour at 212° F.

When referring to a steam generator having a power output of less thanor equal to about 6 boiler horsepower, what is meant is at least one of:(i) a steam boiler dedicated to the apparatus, having a power output ofless than or equal to about 6 boiler horsepower; or (ii) another sourceof steam which provides less than or equal to about 6 boiler horsepowerto the apparatus. There may be steam generators already present incertain manufacturing facilities in which the apparatus may be placed.In these instances, it may be possible to utilize the existing steamboilers in order to provide steam to the present apparatus.

While expandable polymeric microspheres are discussed herein with regardto use in cementitious compositions, the present apparatus is notlimited to providing expanded polymeric microspheres for use incementitious compositions. Rather, the present apparatus may be used toprovide expanded polymeric microspheres for use in any products ofmanufacture in which expanded polymeric microspheres may be included.

In certain embodiments, the apparatus may consume less than or equal toabout 70 kW during steady-state operation. In certain embodiments, theapparatus may consume less than or equal to about 60 kW duringsteady-state operation. In certain embodiments, the apparatus mayconsume less than or equal to about 50 kW during steady-state operation.In certain embodiments, the apparatus may consume less than or equal toabout 45 kW during steady-state operation.

In certain embodiments, the apparatus may be capable of expanding fromabout 0.1 gal/min to about 3 gal/min (from about 0.5 L/min to about 14L/min) of the fluid material comprising unexpanded, expandable polymericmicrospheres during steady-state operation. In certain embodiments, theapparatus may be capable of producing from about 0.2 gal/min to about 2gal/min (from about 0.9 L/min to about 9 L/min) of the fluid materialcomprising unexpanded, expandable polymeric microspheres duringsteady-state operation. In certain embodiments, the apparatus may becapable of producing from about 0.4 gal/min to about 1 gal/min (fromabout 1.8 L/min to about 5 L/min) of the fluid material comprisingunexpanded, expandable polymeric microspheres during steady-stateoperation.

In certain embodiments, the fluid material comprising unexpanded,expandable polymeric microspheres may comprise from about 1% to about50% by volume of unexpanded, expandable polymeric microspheres. Incertain embodiments, the fluid material comprising unexpanded,expandable polymeric microspheres may comprise from about 5% to about40% by volume of unexpanded, expandable polymeric microspheres. Incertain embodiments, the fluid material comprising unexpanded,expandable polymeric microspheres may comprise from about 10% to about30% by volume of unexpanded, expandable polymeric microspheres.

Without wishing to be limited by theory, the function of the apparatusmay be described as follows. A fluid material comprising unexpanded,expandable polymeric microspheres may include water (and/or othersuitable fluid(s)) and the unexpanded, expandable polymericmicrospheres, and may also include other admixtures for cementitiouscompositions, if the expanded polymeric microspheres will be used in acementitious composition. The fluid material comprising the unexpanded,expandable polymeric microspheres is contacted with steam within thetreatment zone, such that the unexpanded, expandable polymericmicrospheres are subjected to increased temperature, which results inexpansion of the expandable polymeric microspheres. In certainembodiments, the expandable polymeric microspheres may also be subjectedto increased pressure within the treatment zone, and upon exiting thetreatment zone, optionally via the back pressure generator, theexpandable polymeric microspheres may experience a pressure drop equalto the difference between the pressure in the treatment zone and thepressure in the environment outside the treatment zone. This decrease inpressure may result in further expansion of the expandable polymericmicrospheres.

In certain embodiments, the temperature inside the treatment zone may befrom about 80° C. (176° F.) to about 160° C. (320° F.), in certainembodiments from about 100° C. (212° F.) to about 160° C. (320° F.), incertain embodiments from about 105° C. (221° F.) to about 145° C. (293°F.), in certain embodiments from about 135° C. (275° F.) to about 145°C. (293° F.). In certain embodiments, the pressure inside the treatmentzone may be from about 46.1 kPa (6.69 psi) to about 618.1 kPa (89.65psi), in certain embodiments from about 101.3 kPa (14.69 psi) to about618.1 kPa (89.65 psi), in certain embodiments from about 120 kPa (17.4psi) to about 420 kPa (60.9 psi), in certain embodiments from about 315kPa (45.7 psi) to about 420 kPa (60.9 psi).

In certain embodiments, the fluid material conduit may comprise aparticle dispersing device at the end of the fluid material conduitproximate to the junction between the fluid material conduit and thesteam conduit. The particle dispersing device acts to separate theunexpanded, expandable polymeric microspheres, in order to increase theamount of surface area of unexpanded, expandable polymeric microsphereswhich is contacted with steam. In certain embodiments, the particledispersing device may be a nozzle.

The fluid material comprising the expanded, expandable polymericmicrospheres may then be added to or mixed with process water or otherliquid admixtures, and then incorporated into a cementitious compositionor other product of manufacture. Alternatively, the fluid materialcomprising the expanded, expandable polymeric microspheres may beincorporated directly into a cementitious composition (before or duringmixing of the cementitious composition) or other product of manufacturewithout first adding the fluid material to process water or other liquidadmixtures.

The back pressure generator is capable of restricting and/or controllingthe flow of the fluid material and steam through the treatment zone, toensure that the temperature within the treatment zone is sufficient toallow the expandable polymeric microspheres to expand to a desireddegree. In certain embodiments, the back pressure generator may alsoprovide increased pressure within the treatment zone, in order to allowfurther expansion of the expandable polymeric microspheres, if theexpandable polymeric microspheres experience a pressure drop uponexiting the treatment zone. The back pressure generator may comprise,for example, a flow control valve or a flow restriction device, such asan orifice nozzle. Alternatively or additionally, in certainembodiments, the back pressure generator may comprise: (i) a length ofconduit sufficient to impede flow through the treatment zone, such thatthe temperature and/or pressure inside the treatment zone are maintainedor increased; and/or (ii) a conduit which has an interior size which issmaller than the interior size of either or both of the fluid materialconduit or the steam conduit, such that the temperature and/or pressureinside the treatment zone are maintained or increased; and/or (iii) aconduit which has an irregular interior wall pattern, such as a rifledconduit, such that the temperature and/or pressure inside the treatmentzone are maintained or increased.

In certain embodiments, the apparatus has a footprint which allows theapparatus to be placed inside a manufacturing facility which uses theexpanded expandable polymeric microspheres in products of manufacturewithout substantially adversely affecting production of the products ofmanufacture. As used herein, the term “footprint” means the horizontalarea of the apparatus, e.g., the floor space consumed by the apparatuswhen placed inside a manufacturing facility. For example, the apparatusmay be placed inside an existing cementitious composition manufacturingfacility without substantially affecting production of the cementitiouscomposition and without requiring adding space to the manufacturingfacility. Similar arrangements are possible in manufacturing facilitieswhich produce other products. The footprint of the apparatus may be lessthan or equal to about 60 ft² in some embodiments.

In certain embodiments, it may be desirable to allow the expanded,expandable polymeric microspheres to achieve a shell stabilizedcondition after leaving the treatment zone, prior to incorporating theexpanded, expandable polymeric microspheres into water and/or acementitious composition. It is possible that injecting the expanded,expandable polymeric microspheres directly into water and/or acementitious composition may cause the microspheres to deform, which maybe undesirable when utilizing the microspheres in certain products ofmanufacture. By “shell stabilized condition”, it is meant the conditionat which the expanded, expandable polymeric microspheres will no longerdeform, after being expanded by the expansion process.

Without wishing to be limited by theory, it is believed that microspheredeformation may be caused by at least partial reliquification of theblowing agent used to expand the expandable polymeric microspheres. Theat least partial reliquification of the blowing agent may result innegative pressure inside the expanded, expandable polymericmicrospheres. In order to avoid microsphere deformation in theseconditions, it is necessary to allow the pressure inside the expandedmicrospheres to equilibrate to the pressure of the environment externalto the microspheres. This may be accomplished by allowing a gas, such asair, to penetrate the microspheres to equilibrate the pressure insidethe microspheres to offset the decrease in pressure caused by the atleast partial reliquification of the blowing agent.

Allowing the expanded, expandable polymeric microspheres to achieve ashell stabilized condition may be accomplished by utilizing a chamber influid communication with the outlet end of the treatment zone, whereinthe chamber provides sufficient cooling and residence time to allow theexpanded microspheres to achieve the shell stabilized condition in orderto prevent deformation of the expanded microspheres. In certainembodiments, any suitable fluid, such as air, may be fed to the inlet ofthe chamber in order to cool the expanded, expandable polymericmicrospheres to the shell stabilized condition. In certain embodiments,the outlet end of the chamber may be in fluid communication with avessel which collects the expanded, expandable polymeric microspheres,and the vessel may optionally include a volume of water into which themicrospheres may be dispersed. In certain embodiments, the chamber maycomprise a length of conduit, such as a pipe or a hose.

In certain embodiments, the apparatus may be supplied with sources ofwater and electricity provided by a manufacturing facility in which theapparatus may be placed. Aside from utilizing water and electricityprovided by the manufacturing facility, the apparatus may not otherwisesignificantly affect the operation and/or efficiency of themanufacturing facility, in that the apparatus may be placed in anunobtrusive location within the facility such that the work flow in thefacility need not be substantially altered to accommodate the apparatus.

The expanded polymeric microspheres provide void spaces in cementitiouscompositions prior to final setting, and such void spaces act toincrease the freeze-thaw durability of the cementitious material.Expanded polymeric microspheres introduce voids into cementitiouscompositions to produce a fully formed void structure in cementitiouscompositions which resists concrete degradation produced bywater-saturated cyclic freezing and does not rely on air bubblestabilization during mixing of cementitious compositions. Thefreeze-thaw durability enhancement produced with the expanded polymericmicrospheres is based on a physical mechanism for relieving stressesproduced when water freezes in a cementitious material. In conventionalpractice, properly sized and spaced voids are generated in the hardenedmaterial by using chemical admixtures to stabilize the air voidsentrained into a cementitious composition during mixing. In conventionalcementitious compositions these chemical admixtures as a class arecalled air entraining agents. Use of expanded polymeric microspheres toform a void structure in cementitious compositions does not require theproduction and/or stabilization of air that has been entrained duringthe mixing process.

The use of expanded polymeric microspheres substantially eliminates someof the practical problems encountered in the current art. It also makesit possible to use some materials, i.e., low grade, high-carbon fly ash,which may be landfilled because it is considered unusable inair-entrained cementitious compositions without further treatment. Thisresults in cement savings, and therefore economic savings. As the voids“created” by this approach are much smaller than those obtained byconventional air-entraining agents, the volume of expanded polymericmicrospheres that is required to achieve the desired durability is alsomuch lower than in conventional air entrained cementitious compositions.Therefore, a higher compressive strength can be achieved at the samelevel of protection against freezing and thawing damage. Consequently,the most expensive component used to achieve strength, i.e., cement, canbe saved.

Expandable microspheres and expanded microspheres produced using thesubject apparatus may be useful in various applications such as papermaking, printing inks, putties, sealants, toy-clays, underbody coatings,adhesives, debonding of adhesives, artificial leather, genuine leather,paint, non-woven materials, paper and board, coatings for variousmaterials such as paper, board, plastics, metals and textile,explosives, cable insulations, thermoplastics (such as polyethylene,polyvinyl chloride, and ethylene-vinylacetate) or thermoplasticelastomers (such as styrene-ethylene-butylene-styrene co-polymer,styrene-butadiene-styrene co-polymer, thermoplastic polyurethanes andthermoplastic polyolefins), styrene-butadiene rubber, natural rubber,vulcanized rubber, silicone rubbers, thermosetting polymers (such asepoxies, polyurethanes and polyesters).

Expanded microspheres may also be used in applications such as putties,sealants, toy-clays, genuine leather, paint, explosives, cableinsulations and thermosetting polymers (like epoxies, polyurethanes andpolyesters). In some cases it may be possible to use a mixture ofexpanded and expandable microspheres, for example in underbody coatings,silicone rubbers and light weight foams.

The expandable polymeric microspheres may be comprised of a polymer thatis at least one of polyethylene, polypropylene, polymethyl methacrylate,poly-o-chlorostyrene, polyvinyl chloride, polyvinylidene chloride,polyacrylonitrile, polymethacrylonitrile, polystyrene, and copolymersthereof, such as copolymers of vinylidene chloride-acrylonitrile,polyacrylonitrile-copolymethacrylonitrile, polyvinylidenechloride-polyacrylonitrile, or vinyl chloride-vinylidene chloride, andthe like. As the microspheres are composed of polymers, the wall may beflexible, such that it moves in response to pressure. The material fromwhich the microspheres are to be made, therefore, may be flexible, and,in certain embodiments, resistant to the alkaline environment ofcementitious compositions. Without limitation, suitable expandablepolymeric microspheres are available from Akzo Nobel Pulp andPerformance Chemicals, Inc. (Duluth, Ga.), an AkzoNobel company, underthe trade name EXPANCEL®.

In certain embodiments, the unexpanded, expandable polymericmicrospheres may have an average diameter of about 100 μm or less, incertain embodiments about 50 μm or less, in certain embodiments about 24μm or less, in certain embodiments about 16 μm or less, in certainembodiments about 15 μm or less, in certain embodiments about 10 μm orless, and in other embodiments about 9 μm or less. In certainembodiments, the average diameter of the unexpanded polymericmicrospheres may be from about 10 μm to about 16 μm, in certainembodiments from about 6 μm to about 9 μm, in certain embodiments fromabout 3 μm to about 6 μm, in certain embodiments from about 9 μm toabout 15 μm, and in other embodiments from about 10 μm to about 24 μm.The polymeric microspheres may have a hollow core and compressible wall.The interior portion of the polymeric microspheres comprises a voidcavity or cavities that may contain gas (gas filled) or liquid (liquidfilled).

In certain embodiments, the expanded, expandable polymeric microspheresmay have an average diameter of about 200 to about 900 μm, in certainembodiments, about 40 to about 216 μm, in certain embodiments about 36to about 135 μm, in certain embodiments about 24 to about 81 μm, and incertain embodiments about 12 to about 54 μm.

The diameters expressed above are volume-average diameters. The diameterof the unexpanded and/or expanded, expandable polymeric microspheres maybe determined by any method which is known in the art. For example, thevolume-average diameter of the expandable polymeric microspheres may bedetermined by a light-scattering technique, such as by utilizing a lightscattering device available from Malvern Instruments Ltd(Worcestershire, UK).

It has been found that the smaller the diameter of the expandablepolymeric microspheres, the smaller the amount of the microspheres thatis required to achieve the desired freeze-thaw damage resistance incementitious compositions. This is beneficial from a performanceperspective, in that a smaller decrease in compressive strength occursby the addition of the microspheres, as well as an economic perspective,since a smaller amount of spheres is required. Similarly, the wallthickness of the polymeric microspheres may be optimized to minimizematerial cost, but to ensure that the wall thickness is adequate toresist damage and/or fracture during mixing, placing, consolidating andfinishing processes of the cementitious composition.

In certain embodiments, the apparatus further comprises a control deviceto manually and/or automatically control the function of the apparatus.The control device may comprise, for example, a bank of mechanicalcontrols which operate the apparatus. The control device mayalternatively or additionally comprise a processer. For example, thecontrol device may be a computer including a processor and display,which would allow an operator to electronically control the device viathe display and processor. In certain embodiments, the control devicemay include a programmable logic controller, a human machine interfacedisplay device, and various mechanical controls which may be operated bythe programmable logic controller, such that a human will be able tomanually and/or automatically control the apparatus through the humanmachine interface display device and programmable logic controller.

The control device may also be capable of communicating with a mastercontrol device which controls one or more other apparatus or functionswithin a manufacturing facility, such that the master control device iscapable of controlling the control device of the apparatus. In thismanner, the apparatus may be capable of being controlled automaticallyby the master control device in order to provide expanded expandablepolymeric microspheres during production of products of manufacture inthe manufacturing facility.

In certain embodiments, the apparatus may further comprise a manualand/or automatic site gauge engaged with the fluid material conduit. Incircumstances in which the expanded, expandable polymeric microsphereswill be used in products of manufacture which are subject to governmentregulation, it may be necessary to verify the contents of the fluidmaterial during operation of the apparatus. For example, if the expandedmicrospheres are to be used in a cementitious composition, it may benecessary to verify the amount of expandable microspheres in the fluidmaterial, prior to incorporation in the cementitious composition, inorder to satisfy certain government regulations dictating the amount ofexpanded microspheres required to provide a certain level of protectionagainst freeze-thaw damage.

The site gauge may be viewed manually, such as by an operator lookingthrough the site gauge to verify the presence of expandable polymericmicrospheres in the fluid material. Alternatively or additionally, thesite gauge may be operated automatically, such as by an automated ballvalve which redirects a portion of the fluid material into a glass vialfor inspection. In certain embodiments, the site gauge may also includean outlet so that a portion of the fluid material may be removed foranalysis.

In certain embodiments, the inside diameter of the fluid materialconduit may be from about 0.2 to about 1.5 inches (from about 0.5 toabout 3.8 cm). In certain embodiments, the treatment zone may comprise atreatment conduit. The inside diameter of the treatment conduit may befrom about 0.1 to about 0.75 inches (from about 0.25 to about 1.9 cm).In certain embodiments, the inside diameter of the fluid materialconduit and/or the treatment conduit may be dependent upon the desiredflow rate of the fluid material and the power output of the steamgenerator. In certain embodiments, the inside diameter of the treatmentconduit may be about half the inside diameter of the fluid materialconduit.

In certain embodiments, the steam conduit and the fluid material conduitmay be joined via a conduit junction proximate to an inlet end of thetreatment zone or treatment conduit. For example, the steam conduit andthe fluid material conduit may be joined via a conduit junction engagedwith an inlet end of the treatment zone or treatment conduit. In certainembodiments, the back pressure generator may be engaged with an outletend of the treatment zone or treatment conduit.

In certain embodiments, the apparatus further comprises: (f) a controldevice to manually and/or automatically control the function of theapparatus; and (g) a manual and/or automatic site gauge engaged with thefluid material conduit; wherein: (i) the treatment zone comprises atreatment conduit; (ii) the steam conduit and the fluid material conduitconverge via a conduit junction engaged with an inlet end of thetreatment conduit; and (iii) the back pressure generator is engaged withan outlet end of the treatment conduit.

In certain embodiments, provided is a system for providing expandedpolymeric microspheres comprising the apparatus described above and atleast one batch tank to receive the expanded expandable polymericmicrospheres. In certain embodiments, the system may comprise aplurality of batch tanks to receive the expanded polymeric microspheres.The batch tank(s) may be used to temporarily store the expandedpolymeric microspheres prior to use in products of manufacture. Incertain embodiments, the batch tank(s) may comprise at least one mixingdevice in order to maintain a uniform suspension of the expanded,expandable polymeric microspheres residing in the batch tank(s).Providing a plurality of batch tanks may increase the efficiency of thesystem, in that the apparatus may be run constantly for a period of timein order to fill all of the plurality of batch tanks with expandedpolymeric microspheres for later use in products of manufacture. In thisway, the apparatus would not have to be started and stopped each timeexpanded polymeric microspheres are needed, avoiding multiple apparatusstarting operations, which may require additional energy in order tostart the apparatus numerous times.

In certain embodiments, the source of the fluid material is not a partof the apparatus. For example, the source of the fluid material may beat least one fluid material vessel proximate or remote to the apparatus,which can be adapted to be in fluid communication with the fluidmaterial conduit. A specific non-limiting example is a fluid materialvessel connected to the apparatus via a removable conduit engaged withthe fluid material conduit.

In certain embodiments, provided is a system for providing expandedpolymeric microspheres comprising the apparatus described above and atleast one fluid material vessel in fluid communication with the fluidmaterial conduit.

Also provided is a system for providing expanded polymeric microspherescomprising: (i) an apparatus for expanding a fluid material comprisingunexpanded, expandable polymeric microspheres, the apparatus comprising:(a) a steam generator having a power output of less than or equal toabout 6 boiler horsepower; (b) a steam conduit in fluid communicationwith the steam generator; (c) a fluid material conduit in fluidcommunication with a source of the fluid material; (d) a treatment zonein fluid communication with the steam generator via the steam conduit,and with the fluid material conduit, such that the fluid material iscontacted by steam within the treatment zone; and (e) a back pressuregenerator in fluid communication with the treatment zone, capable ofincreasing pressure in the treatment zone, which results in expansion ofthe expandable polymeric microspheres when the fluid material exits thetreatment zone; (ii) at least one fluid material vessel in fluidcommunication with the fluid material conduit; and (iii) at least onebatch tank to receive the expanded expandable polymeric microspheres. Incertain embodiments, the system may further comprise a site gaugeengaged with the fluid material conduit. In certain embodiments, thesystem may comprise a plurality of batch tanks to receive the expandedpolymeric microspheres. In certain embodiments, the at least one batchtank may comprise at least one mixing device.

FIG. 1 depicts embodiments of the apparatus and systems describedherein. Apparatus 10 comprises a steam generator 12 in fluidcommunication with a steam conduit 14, which is in turn in fluidcommunication with a conduit junction 24. A fluid material conduit 16,optionally including a site gauge 22 engaged therewith, is in fluidcommunication with the conduit junction 24. The conduit junction 24 isproximate to or engaged with an inlet end of a treatment zone 18. A backpressure generator 20 is engaged with an outlet end of the treatmentzone 18. The apparatus may be a part of a system 30 which includes atleast one batch tank 26 in fluid communication with the treatment zone18 and at least one fluid material vessel 28 in fluid communication withthe fluid material conduit 16. A control device 32 may be in electroniccommunication with any number of the items which make up the apparatus10, and may additionally control aspects of the system 30.

FIG. 2 depicts embodiments of the apparatus and systems describedherein. Apparatus 10 comprises a steam generator 12 in fluidcommunication with a steam conduit 14, which is in turn in fluidcommunication with a conduit junction 24. A fluid material conduit 16,optionally including a site gauge 22 engaged therewith, is in fluidcommunication with the conduit junction 24. The conduit junction 24 isproximate to or engaged with an inlet end of a treatment zone 18. Thefluid material conduit optionally includes a particle dispersing device34 at the end of the fluid material conduit prozimate to the conduitjunction 24. A back pressure generator 20 is engaged with an outlet endof the treatment zone 18. The apparatus may be a part of a system 30which includes at least one batch tank 26 in fluid communication withthe treatment zone 18 and at least one fluid material vessel 28 in fluidcommunication with the fluid material conduit 16. The system 30 mayinclude a chamber 36 for allowing the expanded, expandable polymericmicrospheres to achieve a shell stabilized condition. A control device32 may be in electronic communication with any number of the items whichmake up the apparatus 10, and may additionally control aspects of thesystem 30.

The following example is set forth merely to further illustrate thesubject apparatus and systems. The illustrative examples should not beconstrued as limiting the apparatus or systems in any manner.

A dispersion of unexpanded, expandable polymeric microspheres in wateris provided to a fluid material conduit 16. A steam generator 12 havinga power output of less than or equal to about 6 boiler horsepowerproduces steam, which is provided to a steam conduit 14. The fluidmaterial conduit 16 and the steam material conduit 14 meet at a Tjunction 24 and enter the treatment zone 18. Inside the treatment zone18, the steam heats and pressurizes the microsphere dispersion, causinga small amount of expansion of the microspheres and softening the shellof the microspheres. A backpressure generator 20 in the form of anorifice nozzle is engaged with the outlet end of the treatment zone 18,increasing the pressure in the treatment zone 18. The microspheredispersion passes through the backpressure generator 20 and experiencesa pressure drop equal to the difference between the pressure inside thetreatment zone 18 and the pressure in the environment outside thetreatment zone. The pressure drop causes the microspheres to expand. Themicrospheres are then either immediately used in a product ofmanufacture, such as a cementitious composition, or are stored for lateruse.

In a first embodiment, a subject apparatus may comprise: (a) a steamgenerator having a power output of less than or equal to about 6 boilerhorsepower; (b) a steam conduit in fluid communication with the steamgenerator; (c) a fluid material conduit in fluid communication with asource of a fluid material, wherein the fluid material comprisesunexpanded, expandable polymeric microspheres; (d) a treatment zone influid communication with the steam generator via the steam conduit, andwith the fluid material conduit, such that the fluid material iscontacted by steam within the treatment zone; and (e) a back pressuregenerator in fluid communication with the treatment zone, capable ofincreasing pressure in the treatment zone, which results in expansion ofthe expandable polymeric microspheres when the fluid material exits thetreatment zone.

The apparatus of the first embodiment may further include that theapparatus consumes less than or equal to about 70 kw, optionally lessthan or equal to about 60 kW, optionally less than or equal to about 50kW, optionally less than or equal to about 45 kW, during steady-stateoperation.

The apparatus of either or both of the first or subsequent embodimentsmay further include that the apparatus is capable of expanding fromabout 0.1 gal/min to about 3 gal/min of the fluid material comprisingunexpanded, expandable polymeric microspheres during steady-stateoperation, optionally from about 0.2 gal/min to about 2 gal/min of thefluid material comprising unexpanded, expandable polymeric microspheresduring steady-state operation, optionally from about 0.4 gal/min toabout 1 gal/min of the fluid material comprising unexpanded, expandablepolymeric microspheres during steady-state operation.

The apparatus of any of the first or subsequent embodiments may furtherinclude that the fluid material comprises from about 1% to about 50% byvolume of unexpanded, expandable polymeric microspheres, optionally fromabout 5% to about 40% by volume of unexpanded, expandable polymericmicrospheres, optionally from about 10% to about 30% by volume ofunexpanded, expandable polymeric microspheres.

The apparatus of any of the first or subsequent embodiments may furtherinclude that the apparatus has a footprint which allows the apparatus tobe placed inside a manufacturing facility which uses the expandedexpandable polymeric microspheres in products of manufacture withoutsubstantially affecting production of the products of manufacture. Thefootprint of the apparatus may be less than or equal to about 60 ft².

The apparatus of any of the first or subsequent embodiments may furthercomprise a control device to manually and/or automatically control thefunction of the apparatus. The control device may comprise a processor.

The apparatus of any of the first or subsequent embodiments may furthercomprise a manual and/or automatic site gauge engaged with the fluidmaterial conduit.

The apparatus of any of the first or subsequent embodiments may furtherinclude that the inside diameter of the fluid material conduit may befrom about 0.2 to about 1.5 inches.

The apparatus of any of the first or subsequent embodiments may furtherinclude that the treatment zone comprises a treatment conduit. The steamconduit and the fluid material conduit may be joined via a conduitjunction proximate to an inlet end of the treatment conduit. The steamconduit and the fluid material conduit may be joined via a conduitjunction engaged with an inlet end of the treatment conduit. The backpressure generator may engaged with an outlet end of the treatmentconduit. The inside diameter of the treatment conduit may be from about0.1 to about 0.75 inches. The inside diameter of the treatment conduitmay be about half the inside diameter of the fluid material conduit.

The apparatus of any of the first or subsequent embodiments may furtherinclude that the temperature inside the treatment zone is from about 80°C. to about 160° C., optionally from about 100° C. to about 160° C.,further optionally from about 105° C. to about 145° C., furtheroptionally from about 135° C. to about 145° C.

The apparatus of any of the first or subsequent embodiments may furtherinclude that the pressure inside the treatment zone is from about 46.1kPa to about 618.1 kPa, optionally from about 101.3 kPa to about 618.1kPa, further optionally from about 120 kPa to about 420 kPa, furtheroptionally from about 315 kPa to about 420 kPa.

The apparatus of any of the first or subsequent embodiments may furtherinclude that the fluid material conduit comprises a particle dispersingdevice at the end of the fluid material conduit proximate to thejunction between the fluid material conduit and the steam conduit.

The apparatus of any of the first or subsequent embodiments may furthercomprise: (f) a control device to manually and/or automatically controlthe function of the apparatus; and (g) a manual and/or automatic sitegauge engaged with the fluid material conduit; wherein: (i) thetreatment zone comprises a treatment conduit; (ii) the steam conduit andthe fluid material conduit converge via a conduit junction engaged withan inlet end of the treatment conduit; and (iii) the back pressuregenerator is engaged with an outlet end of the treatment conduit.

In a second embodiment, a subject system for providing expandedpolymeric microspheres may comprise the apparatus of any of the first orsubsequent embodiments and at least one batch tank to receive theexpanded expandable polymeric microspheres. The system may comprise aplurality of batch tanks to receive the expanded polymeric microspheres.The at least one batch tank may comprise at least one mixing device.

In a third embodiment, a subject system for providing expanded polymericmicrospheres may comprise the apparatus of any of the first orsubsequent embodiments and at least one fluid material vessel in fluidcommunication with the fluid material conduit.

In a fourth embodiment, a subject system for providing expandedpolymeric microspheres may comprise: (i) an apparatus for expanding afluid material comprising unexpanded, expandable polymeric microspheres,the apparatus comprising: (a) a steam generator having a power output ofless than or equal to about 6 boiler horsepower; (b) a steam conduit influid communication with the steam generator; (c) a fluid materialconduit in fluid communication with a source of the fluid material; (d)a treatment zone in fluid communication with the steam generator via thesteam conduit, and with the fluid material conduit, such that the fluidmaterial is contacted by steam within the treatment zone; and (e) a backpressure generator in fluid communication with the treatment zone,capable of increasing pressure in the treatment zone, which results inexpansion of the expandable polymeric microspheres when the fluidmaterial exits the treatment zone; (ii) at least one fluid materialvessel in fluid communication with the fluid material conduit; and (iii)at least one batch tank to receive the expanded expandable polymericmicrospheres. The system may further comprise a site gauge engaged withthe fluid material conduit. The system may further comprise a pluralityof batch tanks to receive the expanded polymeric microspheres. The atleast one batch tank may comprise at least one mixing device.

What is claimed is:
 1. An apparatus comprising: a. a steam generatorhaving a power output during steady-state operation of less than orequal to about 6 boiler horsepower; b. a steam conduit in fluidcommunication with the steam generator; c. a fluid material conduit influid communication with a source of a fluid material, wherein the fluidmaterial comprises unexpanded, expandable polymeric microspheres; d. atreatment zone in fluid communication with the steam generator via thesteam conduit, and with the fluid material conduit, such that the fluidmaterial is contacted by steam within the treatment zone; and e. a backpressure generator in fluid communication with the treatment zone,capable of increasing pressure in the treatment zone, which results inexpansion of the expandable polymeric microspheres when the fluidmaterial exits the treatment zone.
 2. The apparatus of claim 1, whereinthe apparatus consumes less than or equal to about 70 kw duringsteady-state operation.
 3. The apparatus of claim 1, wherein theapparatus has a footprint which allows the apparatus to be placed insidea manufacturing facility which uses the expanded expandable polymericmicrospheres in products of manufacture without substantially adverselyaffecting production of the products of manufacture.
 4. The apparatus ofclaim 3, wherein the footprint of the apparatus is less than or equal toabout 60 ft².
 5. The apparatus of claim 1, further comprising a manualand/or automatic site gauge engaged with the fluid material conduit. 6.The apparatus of claim 1, wherein the inside diameter of the fluidmaterial conduit is from about 0.2 to about 1.5 inches.
 7. The apparatusof claim 1, wherein the treatment zone comprises a treatment conduit. 8.The apparatus of claim 7, wherein the steam conduit and the fluidmaterial conduit are joined via a conduit junction proximate to an inletend of the treatment conduit.
 9. The apparatus of claim 7, wherein theback pressure generator is engaged with an outlet end of the treatmentconduit.
 10. The apparatus of claim 1, wherein the temperature insidethe treatment zone is from about 80° C. to about 160° C.
 11. Theapparatus of claim 1, wherein the pressure inside the treatment zone isfrom about 46.1 kPa to about 618.1 kPa.
 12. The apparatus of claim 1,further comprising: f. a control device to manually and/or automaticallycontrol the function of the apparatus; and g. a manual and/or automaticsite gauge engaged with the fluid material conduit; wherein: i. thetreatment zone comprises a treatment conduit; ii. the steam conduit andthe fluid material conduit converge via a conduit junction engaged withan inlet end of the treatment conduit; and iii. the back pressuregenerator is engaged with an outlet end of the treatment conduit.
 13. Asystem for providing expanded polymeric microspheres comprising theapparatus of claim 1 and at least one batch tank to receive the expandedexpandable polymeric microspheres, optionally wherein the at least onebatch tank comprises at least one mixing device.
 14. The system of claim13, comprising a plurality of batch tanks to receive the expandedpolymeric microspheres.
 15. The apparatus of claim 1, wherein the backpressure generator comprises at least one of: (i) a length of conduitsufficient to impede flow through the treatment zone, such that thetemperature and/or pressure inside the treatment zone are maintained orincreased; (ii) a conduit which has an interior size which is smallerthan the interior size of either or both of the fluid material conduitor the steam conduit, such that the temperature and/or pressure insidethe treatment zone are maintained or increased; or (iii) a conduit whichhas an irregular interior wall pattern, optionally a rifled conduit,such that the temperature and/or pressure inside the treatment zone aremaintained or increased.
 16. The apparatus of claim 1, wherein theapparatus consumes less than or equal to about 45 kW during steady-stateoperation.
 17. The apparatus of claim 7, wherein the steam conduit andthe fluid material conduit are joined via a conduit junction engagedwith an inlet end of the treatment conduit.
 18. The apparatus of claim1, wherein the temperature inside the treatment zone is from about 105°C. to about 145° C.
 19. The apparatus of claim 1, wherein the pressureinside the treatment zone is from about 120 kPa to about 420 kPa.